Axles, such as for bicycles

ABSTRACT

A suspension for a two-wheeled vehicle includes first and second fork legs. Each fork leg includes a dropout. Each dropout has an opening therethrough. At least a portion of one of the openings is threaded. Each of the dropouts includes a split-clamp pinch bearing defining the opening and operable between an open position and a locked position, and a hand operable actuator pivoted to the bearing for operation thereof. The suspension further includes a one-piece axle. The axle is disposed through the openings. The axle has a threaded first end engaged with the threaded portion. The axle has an ergonomic grip formed at a second end. The bearing tightly engages an outer surface of the axle in the locked position, thereby rotationally coupling the axle to the dropout.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/362,654, filed Jan. 30, 2009, which is a divisional of U.S. patentapplication Ser. No. 11/674,471, filed Feb. 13, 2007, now abandoned.Each of the aforementioned related patent applications is hereinincorporated by reference in its entirety.

FIELD OF THE INVENTION

The invention is generally directed to the field of axles fortwo-wheeled vehicles. The invention is especially directed to the fieldof bicycle axles especially suitable for use in high stress and/orcompetitive applications, such as downhill, extreme, and free riding.

All patents, patent applications, and other publications, referred toherein are incorporated by reference in their entirety into this patentapplication.

BACKGROUND OF THE INVENTION

Today's high performance two-wheeled vehicle is often subjected toextreme riding conditions. Accordingly, riders expect precise steering,robust construction, and improved resistance to torsional and shearforces.

Therefore, designers seek improvements to, for example, axle technologyand how axles are retained to vehicle frames.

For example, in U.S. Pat. No. 4,632,415 (San Hai), the fork ends havebearings for receiving a spindle that supports a wheel hub. The spindleis one piece and has threads on one end that, when the spindle issupported by its bearings, projects out of its bearing. A nut is thenthreaded onto the threaded end of the spindle to secure the spindle tothe front fork. The fact that the non-threaded, enlarged end of SanHai's spindle appears to have a screwdriver slot implies this design wasnot meant for tool-free use and was certainly not ergonomicallydesigned.

In U.S. Pat. No. 6,109,635 (Maeda), a motorcycle axle having a threadedend for engaging an axle nut is described. The axle nut is then clampedin a split-clamp axle holder. However, the threads of the axle neverengage complementary threads of the axle holder, since there are no suchcomplementary threads.

In U.S. Pat. No. 6,412,803 (Lalikyan), an inverted front fork and wheelassembly for bicycles and motorcycles includes an axle havingnon-circular end portions that are clamped within correspondingnon-circular dropout openings, thereby to increase the torsionalstiffness of the fork.

In U.S. Pat. No. 6,886,894 (Kanchisa), a hub axle is provided that ispreferably a one-piece unitary member made from a suitable rigidmaterial. Similar to the '415 patent mentioned above, the hub axle hasthreads on one end that, when the hub axle is supported by its bearings,projects out of its bearing. A nut is then threaded onto the threads ofthe end of the hub axle to secure the hub axle to the front fork. Also,as with the '415 patent, the fact that the enlarged end of Kanchisa'shead portion is described as being a tool engaging portion, implies thisdesign was not meant for tool-free use and was also certainly notergonomically designed.

In U.S. Pat. No. 7,090,308 (Rose), a multi-component axle assembly formounting a wheel to a vehicle is described. The tubular body, whilehaving a threaded end for engaging complementary threads in one of thedropouts, has at least one slot in each end that allows radialdeformation of the tubular body when the clamp lever is placed in theclamping position.

In the Rockshox TULLIO™ system (see 2002 Rockshox Psylo U-Turn ServiceGuide, pp. 8-10), a simply machined tubular axle member had a threadedbearing end for capture in a threaded split-clamp pinch-bearing and aseparate smooth bearing end for capture in a smoothly machinedsplit-clamp pinch bearing. The TULLIO system included a lever forrotating the axle so that the threads of the TULLIO axle can be capturedby the complementary threads of the split-clamp pinch bearing. Thelever, during non-use, was pivoted until it was parallel with thelongitudinal axis of the axle and then pushed into a stowed positioninside the lever-retaining component. The lever-retaining component wasscrewed into the smooth bearing end of the tubular axle member makingthe TULLIO system a multi-component axle assembly. Clamps were used foropening and closing the split-clamp pinch bearings. The TULLIO system isalso described in GB 2,414,971 (Bartlett).

While in GB 1,336,620 (Mannesmannrohren-Werke GMBH), a method of forminga generic axle (no application mentioned) using forging of a hollow tubeis described, there appears to have been little discussion in the priorart about the methods used to manufacture motorcycle or bicycle axlesand how those methods may be integrated into the axle assembly process(e.g. axle attachment to vehicle).

Some common prior art methods for manufacturing motorcycle or bicycleaxles include machining a tubular or solid metallic extrusion or billetand internally and externally swaging and forming from steel tube stock.These methods are not necessarily cost effective. Additionally, thesemethods do not easily lead to one-piece and ergonomically shaped endproducts.

Accordingly, there is room for improvement within the art.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a cross-section of an axle according to an exemplaryembodiment of the invention.

FIGS. 2A, 2B, and 2C depict an exemplary use for the exemplary axle ofFIG. 1.

FIG. 3 is a high-level block diagram indicating an exemplary method formaking the exemplary axle of FIG. 1.

FIG. 4A and FIG. 4B depict the enlarged portion of the axle body afterthe first forging step.

FIG. 5A and FIG. 5B depict solid and cross-sectional views,respectively, of the axle body after the second forging step

FIG. 6 depicts the grip portion of the exemplary axle after some basicmachining steps.

FIG. 7 depicts the complete axle (except for the lever) after finalmachining.

FIG. 8A and FIG. 8B depict an alternative embodiment of an axleaccording to the invention.

DETAILED DESCRIPTION OF THE DRAWINGS Introduction

This patent application describes the invention in the context of anexemplary embodiment of a front axle for a bicycle and how thatexemplary axle is mounted to an exemplary front bicycle suspension fork.However, the teachings and scope of the invention—especially as relatedto the manufacture of the axle body, itself—are equally applicable to afront or rear wheel of any two-wheeled vehicle.

Basic Axle Structure

FIG. 1 depicts a cross-section of an axle assembly 10 according to anexemplary embodiment of the invention. Axle assembly 10 includes an axlebody 11 having a first end 12 and a second end 13 connected by anelongated tubular body portion 15. The inner wall 15′ of tubular bodyportion 15 defines a through bore 15 a. As will be described below, thefirst and second ends 12, 13, will be processed differently during themanufacture of axle body 11 and have different structures. However, theywill still be parts of a unitary (one-piece) axle body. Positionedbetween the first end 12 and the second end 13 are a first bearingportion 16 and a second bearing portion 17 for mounting in first andsecond dropouts, respectively (see discussion of FIGS. 2A-2C below). Aswill be described below and for the beneficial reasons described below,according to the preferred embodiment of the invention, axle body 11will be forged from a single solid metallic work piece. Typically, themetallic work piece will be a piece of aluminum. However, othermaterials may be used.

First bearing portion 16 includes threads 19 positioned adjacent thefirst end 12 of the axle body 11 and a smooth bearing surface 20inwardly spaced from threads 19 and the first end 12 of axle body 11.Threads 19 are for mounting in complementary threads 101 in acorresponding threaded dropout 99 (see FIG. 2A).

Second bearing portion 17 includes an enlarged diameter (relative to thefirst bearing surface 20) smooth bearing surface 21 for insertion into acorresponding non-threaded and smooth dropout 98 (see discussion ofFIGS. 2A-C below).

The second end 13 of axle body 11 includes an ergonomically designedgrip portion 22. Grip portion 22 may include first and second opposedwings 23 a, 23 b, extending outward from the longitudinal axis of theaxle body 11 beyond the bearing surfaces of axle body 11. Accordingly,under such conditions, the wings 23 a, 23 b would be the widest portionof axle body 11. As shown in FIG. 6, wings 23 a, 23 b have smoothenedends 24 and are shaped, such that in combination with sweeping curvedsurfaces 25, grip portion 22 is ergonomically shaped to be comfortableto hold and allow easy and comfortable tool-free mounting of axleassembly 10 to its corresponding dropouts.

A lever 26 may be provided for rotating axle assembly 10 about islongitudinal axis so that the threads 19 of axle assembly 10 mayinterlock with the threads of the dropout 99. Lever 26 may be pivotable(see curved arrow A-A of FIG. 1) about a fixed pivot point, such as afastener 30, positioned on wing 23 a, between at least first and secondpositions. In lever 26's first position (solid), lever 26 is in itsoperable position to assist in rotating axle assembly 10 about itslongitudinal axis. In lever 26's second position (shadow), lever 26 hasbeen pivoted into its stowed position in a lever recess 26′ (see e.g.FIG. 6 for best view) and is retained in the stowed position by a clipring 27.

In applications where tool-free mounting of axle assembly 10 is notimportant, as shown in FIG. 8A, 8B, it is possible to insert any knownexternal tool T into a tool-receiving portion T′ defined by grip portion22.

Whether lever 26 or an external tool T is used, grip portion 22 andtubular body 15 remain a one-piece axle body 11. This one-piececonstruction reduces production costs as well as opportunities for theaxle components to separate when subjected to extreme forces. Thus, thecurrent exemplary one-piece design is more robust and useful inhigh-stress applications than prior art multi-component designs.

Exemplary Use of Axle

FIG. 2A-2C depict an exemplary use for the exemplary axle assembly 10 ofFIG. 1 and in the form of a bottom portion of an exemplary bicyclesuspension fork. For clarity, such conventional components as the upperportions of the suspension fork, the tire, the wheel and otherassociated hardware have been omitted from FIGS. 2A-2C.

In FIG. 2A, the longitudinal axis of axle assembly 10 is aligned withthe longitudinal axes of the dropouts 98, 99 of the suspension fork. Inthis exemplary embodiment, the dropouts 98, 99 include split-clamp pinchbearings 100, 100′ in lower fork legs 110. Split-clamp pinch bearings100, 100′ substantially surround axle assembly 10 subject to small slits102 formed by the space between opposing clamp ends 103, 103′ that allowthe diameters of the split-clamp pinch bearings 100, 100′ to be variedto clamp or release axle assembly 10 within split-clamp pinch bearings100, 100′.

Split-clamp pinch bearing 100 will have a completely smooth bearing-likesurface finish for engagement with smooth bearing surface 21 of axleassembly 10. Split-clamp pinch bearing 100′ will have a partially smoothbearing-like finish for engagement with bearing surface 20 of axleassembly 10 and threads 101 complementary to threads 19. In FIG. 2A,cammed clamp levers 120 are in their open position allowing slits 102 toexpand to allow axle assembly 10 to be inserted into split-clamp pinchbearings 100, 100′.

In FIG. 2B, axle assembly 10 has been inserted through split-clamp pinchbearings 100, 100′. Axle assembly 10 is then rotated, using for example,lever 26 (see arrow B) or ergonomically shaped grip portion 22 until thecomplementary threads 101 of split-clamp pinch bearing 100′ capture axlethreads 19. This may take approximately 2-3 turns of axle body 11depending upon the pitch and length of the complementary threads 19,101. Typically, the rider can feel when the axle threads 19 and thepinch bore threads 101 have become properly engaged.

In FIG. 2C, cammed clamp levers 120 are in their locked positionsthereby decreasing the sizes of slits 102 by forcing opposing clamp ends103, 103′ towards each other. This clamps axle assembly 10 within eachof the split-clamp pinch bearings 100, 100′. Clamping prevents axleassembly 10 from un-threading itself when the fork and axle assembly 10are subjected to various forces. Finally, lever 26 may be pivoted intoits stowed position in lever recess 26′. When lever 26 is stowed withinlever recess 26′, lever 26 will be substantially flush with the surfaceof the grip portion 22.

While the previous discussion has been in the context of installing theaxle assembly 10, one skilled in the art would recognize that in thecontext of un-installing the axle assembly 10, the above process wouldmerely be reversed.

Exemplary Method of Making the Axle

FIG. 3 is a block diagram depicting the major steps of an exemplarymethod for making the exemplary axle assembly 10 whose structure and useare described herein. As previously mentioned, most typically, the axlewill be made from a metallic material, such as aluminum. Accordingly, ablank, such as a solid aluminum work piece, is provided.

Using, for example, conventional hammer forging machinery (not shown), afirst portion of the solid blank will be forged into a solid enlargedportion 50 (see FIGS. 4A, 4B). Enlarged portion 50 will be shaped by theforging process to have the basic physical characteristics of finishedgrip portion 22, as described above. For example, solid enlarged portion50 will be shaped by forging to have wing precursors 51, wing endprecursors 52, and sweepingly curved side surface precursors 53.

Then, again using conventional hammer forging (or impact extrusion)machinery (not shown), a second portion of the same solid blank will beformed into tubular body portion 15. This early form of axle body 11will have inner walls defining a through bore 15′, but the through bore15′ will be closed off at second end 13 and enlarged portion 50 and openat first end 12 (See FIGS. 5A, 5B), i.e., axle body 11 is not yet openat both ends 12, 13.

Note that it may be possible to combine the two forging steps into onedepending upon, for example, part complexity and sophistication ofavailable machine shop equipment.

After forging, enlarged portion 50 is finally formed into finished gripportion 22, shaped as previously described above. To achieve this, themost basic 2D machining methods can be used to finish manufacturing axlebody 11. No complex 3D surface machining methods, which are typicallyexpensive and tedious to program and implement, are needed.Additionally, if solid billet material was used according to prior artmethods, a large amount of time would be spent removing material toachieve this axle diameter, due to the large diameter of the gripportion.

Thus, according to the exemplary method, for example, using conventionalmachine shop cutting tools, as shown in FIG. 6, the closed end ofenlarged portion 50 can be opened up to form bore 55. This lightens axlebody 11. Furthermore, again using simple end mills or woodruff-cutters,wing precursor 51, end precursor 52, and curved side precursor 53 willbe machined into their final forms, which includes forming lever recess26′. Similarly using a drill and tap, pivot bearing 31 and threadedpivot hole 32, for receiving pivot fastener 30, may be formed.

Then, the outer diameter of the bearing portion 21 and the outerdiameter of tubular body portion 15 are smoothened and dimensionedusing, for example, basic 2D machine tools (not shown) and threads 19may be cut into the surface of axle assembly 10 at its first end 12(FIG. 7). Also, retaining groove 27′ for clip ring 27 will be machined.

Finally, before attaching lever 26 to grip portion 20 via fastener 30,axle assembly 10 may be cleaned, de-burred, polished, and anodized, aswell as treated according to any other known mechanical or chemicalprocessing methods. Additionally, clip ring 27 will be installed intoclip ring retaining groove 27′.

CONCLUSION

While the invention has been described with respect to certain exemplarystructural and method embodiments, the invention shall only be limitedby the following claims.

LIST OF REFERENCE NUMERALS USED

Reference Numeral Item A, B angle of rotation T external tool  T′ toolreceiving portion 10 axle 11 axle body 12 first end 13 second end 15tubular body portion  15a through bore  15′ inner wall 16 first bearingportion 17 second bearing portion 19 threads 20 bearing surface 21bearing surface 22 grip portion 23 wings 24 smoothened ends 25 arcuateedge surface 26 lever  26′ lever recess 27 clip ring  27′ clip ringretaining groove 30 fastener 31 pivot bearing 32 threaded pivot hole 50solid enlarged portion 51 wing precursors 52 wing end precursors 53 sidesurface precursors 55 bore 98, 99 dropouts  100, 100′ pinch bearings101  threads 102  slits 110  lower fork legs 120  cammed clamp levers

1. A suspension for a two-wheeled vehicle, comprising: first and secondfork legs, each fork leg comprising a dropout, each dropout having anopening therethrough, wherein at least a portion of one of the openingsis threaded, and wherein each of the dropouts comprises: a split-clamppinch bearing defining the opening and operable between an open positionand a locked position, and a hand operable actuator pivoted to thebearing for operation thereof; and a one-piece axle: disposed throughthe openings, and having a threaded first end engaged with the threadedportion, wherein the bearing tightly engages an outer surface of theaxle in the locked position, thereby rotationally coupling the axle tothe dropout.
 2. The suspension of claim 1, wherein the actuatorcomprises a lever.
 3. The suspension of claim 1, wherein the axle ismade from aluminum.
 4. The suspension of claim 1, wherein the axle has abore formed therethrough.
 5. The suspension of claim 1, furthercomprising a lever pivoted to a second end of the axle.
 6. Thesuspension of claim 5, wherein the second end of the axle has a recessfor stowing the lever.
 7. The suspension of claim 1, wherein a secondend of the axle has a tool receiving portion for receiving an externaltool.
 8. The suspension of claim 1, wherein the bearing is a bearingsurface.
 9. A suspension for a two-wheeled vehicle, comprising: firstand second fork legs, each fork leg comprising a dropout, each dropouthaving an opening therethrough, wherein at least a portion of one of theopenings is threaded, and wherein at least one of the dropoutscomprises: a split-clamp pinch bearing defining the opening and operablebetween an open position and a locked position, and a hand operableactuator pivoted to the bearing for operation thereof; a one-piece axle:disposed through the openings, and having a threaded first end engagedwith the threaded portion, wherein the bearing tightly engages an outersurface of the axle in the locked position, thereby rotationallycoupling the axle to the dropout; and a lever pivoted to a second end ofthe axle.
 10. The suspension of claim 9, wherein the second end of theaxle has a recess for stowing the lever.
 11. The suspension of claim 9,wherein the actuator comprises a second lever.
 12. The suspension ofclaim 9, wherein the axle is made from aluminum.
 13. The suspension ofclaim 9, wherein the axle has a bore formed therethrough.
 14. Thesuspension of claim 9, wherein the bearing is a bearing surface.